Genome interpretation in trees – genetic and epigenetic factors in stress responses and development

Almost all cells in an organism contain the same genetic information. Nevertheless the genome shows remarkable plasticity in its interpretation. Complex organisms are characterized by impressive developmental transitions and can exhibit an astonishing degree of plasticity in response to their environment. During their long life span, forest tree species are likely to encounter frequent environmental changes, and efficient responses are of paramount importance for individual trees and our forest, e.g. in light of recent and predicted climate change. Our work studies the ability of trees to plastically respond to key external stresses such as drought or salinity, or internal signals involved in developmental transitions. It integrates physiological responses, genomic influences and genome-wide epigenetic patterns. Recent work uncovered not only diversity of organ and genotype-specific adjustments in physiology and transcriptome, but also widespread epigenetic variability that paralleled these responses. The work suggests a molecular mechanism for adding a layer of plasticity in long-lived organisms, and it contributes to our understanding of plant-environment interactions, with applications related to genotype selection for current and future climates.